From: zhouchuangao <zhouchuangao@vivo.com>
To: Jessica Yu <jeyu@kernel.org>, linux-kernel@vger.kernel.org
Cc: zhouchuangao <zhouchuangao@vivo.com>
Subject: [PATCH] kernel/module: Use BUG_ON instead of if condition followed by BUG.
Date: Sat, 17 Apr 2021 03:22:01 -0700 [thread overview]
Message-ID: <1618654921-124063-1-git-send-email-zhouchuangao@vivo.com> (raw)
First:
This patch comes from cocinelle warning.
Second:
BUG_ON uses unlikely in if(). Through disassembly, we can see that
brk #0x800 is compiled to the end of the function.
As you can see below:
......
ffffff8008660bec: d65f03c0 ret
ffffff8008660bf0: d4210000 brk #0x800
Usually, the condition in if () is not satisfied. For the
multi-stage pipeline, we do not need to perform fetch decode
and excute operation on brk instruction.
In my opinion, this can improve the efficiency of the
multi-stage pipeline.
Signed-off-by: zhouchuangao <zhouchuangao@vivo.com>
---
kernel/module.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c
index 3047935..f46fc4f 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1014,8 +1014,8 @@ void __symbol_put(const char *symbol)
};
preempt_disable();
- if (!find_symbol(&fsa))
- BUG();
+ BUG_ON(!find_symbol(&fsa));
+
module_put(fsa.owner);
preempt_enable();
}
--
2.7.4
next reply other threads:[~2021-04-17 10:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-17 10:22 zhouchuangao [this message]
-- strict thread matches above, loose matches on Subject: below --
2021-05-10 1:38 [PATCH] kernel/module: Use BUG_ON instead of if condition followed by BUG zhouchuangao
2021-05-12 12:54 ` Jessica Yu
2021-03-30 12:07 zhouchuangao
2021-04-12 13:04 ` Jessica Yu
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